New study evaluates the climate impact of the IRA

Molly Seltzer, Office of Communications

The 2022 Inflation Reduction Act (IRA), the landmark federal climate law, has committed nearly $400 billion to mitigating climate change. But will it do enough to stave off the worst effects of global warming and get the U.S. to net-zero, the point at which the country emits no more carbon into the atmosphere than it removes?

Nine research teams across the U.S, including a Princeton team led by Jesse Jenkins, have modeled the effect of the IRA on U.S. carbon emissions. (Read a July 8 profile on Jenkins in The Wall Street Journal.)

The research teams found that the IRA will dramatically cut U.S carbon emissions, with economy-wide emissions reductions between 43 and 48% below 2005 levels by 2035, but not enough to reach 50% below peak levels by 2030, as the U.S. has pledged. The results were published in the journal Science on June 29.

“IRA doubles the pace of reductions but should have tripled it to hit our 2030 climate goals and get on the path to net-zero by 2050,” Jenkins says.

By the numbers:

• Before the IRA, the U.S. was cutting its carbon emissions by about 2% per year. With the IRA, Jenkins’ team estimates that pace jumps to about 4% annually.
• To reach 50% below peak levels by 2030 and net-zero over the next three decades, the country would need to cut carbon emissions by about 6% per year.

“We need to build on the historic success of the IRA with robust regulations and additional state and federal policies to close the emissions gap,” Jenkins says.

His team recommends retiring coal plants sooner, improving industrial efficiency, and updating farm and forestry practices to keep carbon out of the atmosphere and get the country closer to its net-zero goals.

This story originally appeared in the July/August 2023 issue of Princeton’s environmental newsletter, The Charge, which reports on Princeton environmental research.